实验9：桥接模式

本次实验属于模仿型实验，通过本次实验学生将掌握以下内容：

1、理解桥接模式的动机，掌握该模式的结构；

2、能够利用桥接模式解决实际问题。

[实验任务]：两个维度的桥接模式

用桥接模式实现在路上开车这个问题，其中，车可以是car或bus，路可以是水泥路或沥青路。

类图 

源代码 

/*** 抽象汽车类*/
public abstract class Vehicle
{protected Road road;//为汽车设置行驶的马路public void setRoad(Road road){this.road = road;}//抽象行驶方法public abstract void drive();
}public class Bus extends Vehicle
{//bus的行驶方法@Overridepublic void drive(){String carType = "bus";this.road.bedrive(carType);}
}public class Car extends Vehicle
{//car的行驶方法@Overridepublic void drive(){String carType = "car";this.road.bedrive(carType);}
}public interface Road
{void bedrive(String carType);
}public class ConcreteRoad implements Road
{//水泥路@Overridepublic void bedrive(String carType){System.out.println(carType+"在水泥路行驶");}
}public class PitchRoad implements Road
{//沥青路@Overridepublic void bedrive(String carType){System.out.println(carType + "在沥青路行驶");}
}import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.File;public class XMLUtil
{public static Object getBean(String args){try{DocumentBuilderFactory dFactory = DocumentBuilderFactory.newInstance();DocumentBuilder builder = dFactory.newDocumentBuilder();Document doc;doc = builder.parse(new File("src/main/resources/config9.xml"));Node classNode = null;NodeList nl = doc.getElementsByTagName("className");if (args.equals("road")){classNode = nl.item(0).getFirstChild();} else if (args.equals("vehicle")){classNode = nl.item(1).getFirstChild();}String cName = classNode.getNodeValue();Class c = Class.forName(cName);Object obj = c.newInstance();return obj;}catch (Exception e){e.printStackTrace();return null;}}
}public class Client
{public static void main(String[] args){//从xml配置文件动态获取汽车类型Vehicle vehicle = (Vehicle) XMLUtil.getBean("vehicle");//动态获取路的类型Road road = (Road) XMLUtil.getBean("road");//给汽车设置行驶的路vehicle.setRoad(road);//调用汽车的行驶方法vehicle.drive();}
}

config9.xml

<?xml version="1.0" encoding="UTF-8"?>
<config><className>Tutorial_9.ConcreteRoad</className><className>Tutorial_9.Bus</className>
</config>

运行效果